User's Manual

16 Calibrating the Exciter © Tait Electronics Limited 2005
Calibrating the VCO
This is step three of calibrating the exciter.
Once you have tuned and calibrated the FCL, you calibrate the VCO at
frequencies across the whole lock band. This involves selecting a sub-band,
adjusting the lock band trimmer, and then moving on-screen sliders to adjust
the deviation to 3 kHz for each of a set of frequencies.
Equipment ■ Tuning tool
■ CTU
■ Modulation meter
■ RF attenuator (only required if you are using a PA)
Setup
To calibrate the VCO
1. Ensure that the Calibration Kit PC is connected to the reciter.
2. Select the Reciter Calibration tab, and double-click VCO Calibration.
The VCO Calibration Wizard appears.
3. Attach an appropriate Load and Modulation meter to the PA or exciter
output, set the meter to measure the peak deviation, and then click Next.
(If you are using a PA, it will now transmit.)
4. Adjust the exciter lock band trimmer until the actual band matches the
desired band. The bands turn green.
5. Click Next. Step 3 of the wizard appears.
6. Calibrate each of the frequencies shown. Follow these steps.
a. Click the option button alongside a frequency.
b. Using the Fine and Coarse arrows, adjust the slider until the deviation
shown on the modulation meter is 3000 Hz (peak).
c. Repeat steps a) and b) until all frequencies for the band are calibrated.
This enables the Next Band button.
7. Click Next Band and repeat steps 4) through 6). Repeat until all
frequencies in all bands have been calibrated.
8. If you are connected to a K-band reciter, click Next. Select which of the
two available bands the reciter will operate on.
9. Click Finish. (If you are using a PA, it will now stop transmitting.)
When you have finished calibrating the VCO, the icon on the Reciter
Calibration tab indicates that this task is complete.
1 Reciter 3 RF attenuator (only required if using a PA)
2 PA (optional) 4 Modulation meter
1 2
3
4